richardson



(No Model.) 2 sheets-sheen. F. W. RCHARDSON.

-BALANGED SLIDE VALVE.v

No. 266,721. Patented 001;. 31, 1882.

f7 WT W (No Model.) 2 sheets-sheet 2.

-P. W. RICHARDSON.

BALANGBD SLIDE VALVE.

110.266,721. Patented 001;. 31, 1882.

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FRED XV. RICHARDSON, OF TROY, NEW YORK.

BALANCED SLI DE-VALVE.

SPECIFICATION forming part of Letters Patent No. 266,721, dated October31, 1882..

Application tiled August 1G, 1882. (No model.)

To all whom it may concern:

Be it known that I, FRED W. RICHARDSON, of Troy, county of Rensselaer,and State of New York, have invented certain new and useful Improvementsin Balanced Valves for SteainFiigiiies, of which the following is afull, clear, and exact description, reference being had totheaccompanying drawings, and to the letters of reference marked thereon.

My invention has relation to slide-valves for steam-engines, and amongthe chief objects of my said invention are the production of asimple,cheap, and efficient valve, which shall afford a high initial pressureof steam in the cylinder at the commencement ofthe stroke of the piston,at the same time require a red need travel of the valve necessary toaccomplish its work, be effectually balanced against the pressure oflive steam in the steam-chest, whereby the amount of wear is reduced,and setting ofthe valve for the cut-off rendered easy, be capable of usein any situation where the ordinary D-valve is now employed, and beefficient in operation without wire-drawing7 when cutting oix short.

lo accomplish these objects my improvements involve certain novel anduseful peculiarities otl construction and relative arrangements orcombinations of parts, all of which will be herein first fullydescribed, and then pointed out in the claims.

ln the accompanying drawings, Figure l is a vertical section through thesteam-chest and adjacent parts of the cylinder upon a plane through theaxis of motion ofthe valve in the direction of line oca/*of Fig. 2. Fig.2 is a plan view ofthe upper part ofthe valve; and Fig. 3 a sectionalview upon aI plane at right angies to that of Fig. l, through line y yof Fig. 2, showing the steam-chest and adjacent parts of the cylinder.Fig. 4 is a perspective View of the valve detached, showing the passagesby which steam enters the space beneath the packing-strips, andindicating by dotted line one form of spring which may be employed inconnection with said strips. These iigures illustrate the constructionand arrangements of the valve and its appendages constructed inaccordance with my improvements, and in al1 the gures like letters ofreference, wherever they occur, indicate corresponding parts.

A A are the inlet-ports leading to the cylinder, and B is theexhaust-port.

O O are the walls ofthe steam-chest, erected upon the cylinder, andthese, with the top plate, D, inclose the. valve.

The valve E is in general form like any ordinary slide-valve, and isprovided with the usual exhaust-cavity, F, but differs from the ordinaryvalve in having a supl'ileinental steam port or channel, G, cored outbetween the exhaust cavity and the exterior or wall of the valve-shell.The valveand valve-seatarc'soproportioned with respect to each otherthat when the steamport in the cylinder begins to open past the edge ofthe valve the edge of the supplemental port Gr also opens past the edgeof the valve-scat. Thus a port of double the area of that ati'orded bythe ordinary slidevalve is obtained, insuring a high initial pressure ofsteam in the cylinder at the commencement of the stroke of the piston,and this with a reduced travel of the valve. These features are veryimportant upon high-speed engines, as upon locomotives, inasmuch as incutting off7 short the opening of the ports is greatly reduced, thusobviating wire-drawing of the steam, which is a common disadvantage. Asthe valve continues to travel theport will continue to open until thevalve commences to move in the opposite direction, when this port beginsto close; but during the time the port has remained open it has had adouble portopening to the position where the valve is traveling short orlinked up.77

In designing the valve for any engine care vshould be taken to lay outthe valve and seat so that steam may not blow through the supplementalport into the exhaust when the valve is at its extreme limit of travelin either direction. The valve with the supplemental port is necessarilyheavier than the common valve, and the increased size of the ports alsocauses an increase of friction. To ohviate this it becomesimportant toett'eetually balance the valve against pressure of steam in thesteam-chest, and this I accomplish in a convenient, simple, andeffective manner by cutting four channels in the top of the valve,(being careful not to cut through into the supplemental port,) two onthe sides and two at the ends for the reception of four independentstrips of east-iron.

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:2 activan (Shown at I-IIIII.) For the accom modation of thesepacking-strips, and to obviate cutting through into the supplementalsteam-port, a square frame is cast on the upper part of the valve, asshown. This frame increases the general height of the valve, and in itare cut the grooves or channels which receive the pack-l ing-strips. Thelonger strips H H are plain rectangular pieces; but the shorter strips II are made with gib-shaped ends to retain them in place. All the stripsmay be provided with light springs, as at S, Fig. 4, to hold themagainst the balance-plate when steam is shut off.

Beneath the cover or top plate, D,islocated the balance-plate K, againstwhich the packing strips H H I I are made to wear. This balance-platehas a plane under surface of sufficient area to cover the space inclosedby the packing-strips at all positions of the valve, and is preferablysecured by use of the hollow studs L L and the bolts M M, passingthrough the top plate and entering the studs; but obviously in someinstances the balance-plate might be otherwise bolted to 'the top plateor cover or might be cast directly therewith.

Steam from the steam chest has access to the under sides of th epacking-strips and forces them at all times during use of the enginesnugly up against the balance-plate, thus effectually excluding livesteam from therectangular spaceinclosed bythe said packing-strips. Thevalve will thus be relieved of an enormous down-pressure` equivalent tothe pressure ot' the steam in the steam-chest upon an 'area equal tothat inclosed by the strips, and may thus move more easily and quicklyand with less friction than otherwise and be more easily shifted toafford the required cut-ott'. The valve will be balanced to the extentof tl'iesurt'ace inclosed by the strips. rIhe packingstrips are held in,steam-tight contact with the inner surface o f thc grooves or channels,plancd to receive them, (as well as with the balance-plate,) by directsteam-pressure, the joint being made complete by the abutting of theends of the long sections against the inner surfaces of the gibbedsections at the four corners.

The upper part of the valve is slightly dished, as plainly shown in Fig.3, and the shallow chamber b, thus formed between it and thebalance-plate,communicates with the exhaust-cavity through a smallperforation, a, always open, (but not opening into the supplementalport.) This perforation relieves the top of the valve of any pressuredue to steam which may escape past the packing-strips, and it alsopresents this arca of the valve (inclosed by the packingstrips) to theatmosphere om the exhaust-pipe. The wall of the perforation a extends npto a level with the top of the valve.

When ruiming with steam shutoff (as in the case of the locomotive) thepartial vacuum in the steam-chest causes the valve to hug thebalance-plate, and thus closes the perforation a against admission offoreign matter-as dust, &c. -which might otherwise be drawn into thecavity b, to the detriment of the packing. N represents a yoke, by'whchthe valve is moved through the medium of the valve-rod O passing througha stuffing-box, I?.

rIhe valve constructed and arranged substantiall y in accordance withthe foregoing explanations has been found in practice to admirablyanswer the several purposes and objects of the invention, as previouslystated.

I do not claimy a balanced valve or packingstrips .in a valve foreffecting the balancing; nor do I claim a supplemental steam -port,broadly, in a steam-engine valve. I am aware that these features, whenseparatelyconsidered, have before been explained.

Iam alsoawarethatin abalanced valveachannel for exhaust-steam has beencored out around the ordinary exhaustcavity, which channel does notcarry live steam, and is not arranged to operate in connection with thesteam-ports, so as to afford the supplemental snpplyoflive steam, afterthe manner above explained. The supplemental port shown hereininconnection with my improved valve must be so located that it will takeand conduct live steam from the valvechest in the manner and at thetimes as above set forth.

Having now fully described my invention, what I claim as new, and desireto secure by Letters Patent, is-

l. In combination with the supplemental port, a balancing device, and anexhaust-cavity in a valve for steam-engines, the perforation or channelconnecting the exhaust with the shallow chamber on top of the valve,said perforation being made through a centrallylocated stud,substantially as and for the purposes set forth.

2. The combination and arrangement of the slide-valve having thesupplemental channel for conveying live steam in the manner explained,the four packingstrips located in grooves cut in the top of the valve,the central perforation connecting the exhaust-cavity, and a shallowchamber formed in the top ot' the valve, and the balance-plate,substantially as shown and described.

In testimony that I claim the foregoing I have hereunto set my hand inthe presence of two witnesses.

FRED w. RICHARDSON.

Vitnesses:

WM. W. TURNER, E. H. VAN DEUsEN.

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